March 2011

Published on March 15, 2011 by

Editorial: Highlights of the CROI 2011

The Conference on Retroviruses and Opportunistic Infections (CROI) is one of the biggest events on the HIV related calendar. One of the hot topics was ‘Pre-Exposure Prophylaxis’ (PrEP). However, questions remain about how this strategy, which provides antiretroviral treatment to HIV negative people – really fits into a world in which the majority of HIV infected persons lack access to treatment. Some other highlights of CROI are also discussed. Although HIV/AIDS dominates the agenda in local epidemiology, SACEMA is not an HIV research organization, and we are pleased to present three articles on very different topics: perioperative cardiovascular disease; a methodological perspective involving carcass surveillance; and an item on how medical research can fail so impressively. We trust you will find something of interest in this edition.

Published on March 15, 2011 by

Why does medical research sometimes get it so wrong?

In 1994 Douglas Altman wrote a highly influential paper in the British Medical Journal entitled ‘the scandal of poor medical research’. It focused on the prevalence of poor design and analysis in medical research, due to a general failure to appreciate the principles underlying scientific research. Addressing these shortcomings would entail better science education, not only of researchers, but also of the public and judiciary. But there is another factor at work; ‘confirmation bias’. This is probably the most widespread and insidious form of bias, where scientists search much harder for evidence to support their pet idea than for evidence to refute it – and weight that evidence accordingly. To show that such matters are not merely of academic interest, two recent examples are considered.

Published on March 15, 2011 by

Perioperative cardiovascular disease and mathematical modelling

It is estimated that worldwide nearly a million people per annum suffer major cardiovascular complications following noncardiac surgery. These complications include cardiac death, myocardial infarction (heart attack) and cardiac arrest. Unfortunately, collaboration in perioperative cardiovascular research remains in its infancy, and only recently there has been the development of large collaborative groups to investigate perioperative cardiovascular outcomes. Furthermore, the epidemiology and pathophysiology of perioperative cardiovascular disease is poorly understood. Mathematical modelling should be considered an integral component of perioperative cardiovascular research due to the nature and complexity of the outcomes associated with these studies.

Short item Published on March 15, 2011

HIV-malaria co-infection

A study conducted in Kenya, Malawi and Tanzania analysed the relationship between malaria and HIV prevalence adjusting for important socio-economic and biological cofactors. This is the first study to report malaria as a risk factor of concurrent HIV infection at the population level. Use was made of large nationally representative samples of 19 735 sexually active Read More

Short item Published on March 15, 2011

Clinic on the Meaningful Modelling of Epidemiological Data

SACEMA, in collaboration with the African Institute for Mathematical Sciences (AIMS), is holding a modelling clinic from 30 May to 10 June 2011 in Muizenberg, Cape Town. The clinic will emphasize the use of data in understanding infectious disease dynamics and engages the participants in epidemiological modelling projects that use real data to grapple with Read More

Short item Published on March 15, 2011

Male circumcision reduces transmission of HPV to female partners

Randomised trials show that male circumcision reduces the prevalence and incidence of high-risk human papillomavirus (HPV) infection in men (1). However, the question was whether it also reduces the prevalence and incidence of high-risk HPV in the female partners of these men. In Rakai, Uganda, two randomised controlled trials of male circumcision where conducted between Read More

Published on March 15, 2011 by

Counting Wildlife Carcasses: Anthrax surveillance in Etosha National Park, Namibia

In Etosha National Park, Namibia, the plains zebra and other herbivores experience outbreaks of anthrax. Anthrax is generally not considered to be a problem in Etosha but rather a natural regulating force in the ecosystem. However, the extent to which anthrax plays this role remains poorly understood. Estimating how many carcasses there really are will help us understand the extent to which anthrax regulates zebra and other host populations. The general approach we take is to think about all the factors that affect the probability any carcass is detected (distance from road, time since death, if and when that road was driven, how long carcasses are scavenged for) and then estimate the number of carcasses that were missed. Keeping track of both how we collect data, in addition to the items of interest themselves, can thereby allow us to tease much more information out of our data as well as avoid biasing our results. And with better estimates of anthrax incidence we can learn more about the role anthrax plays in Etosha and elsewhere.